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#3 More on BIOS calls for the text screen

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Ok, after a very long first and second blog this one will be (hopefully) a bit shorter. Please do read the first two blogs as I will be referring to them. I also will only explain what's new and not what already has been covered. In this blog we will stick to the standard text screen (screen 0) . I'm going to explain some other usefull BIOS calls and we will make a little program with a graphical effect in which we will use loops with counters in it. Clear the screen In MSX BASIC you can use the CLS  instruction to clear the screen. There is a BIOS call to do this in assembly. First go to MSXPen again as we will use this as our programming environment. We will always need our 1 line of BASIC again to run our machine code: 10 BLOAD"PROGRAM.BIN",R  And there are also a few lines of assembly that we will always use:             org 0xD000 ; the address of our program start:             end start ; end of code Personally I always first click on Hello World?   at the
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#2 Hello world (part 2 of 2 - programming)

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Now that we've covered the basic knowledge that we need to write our first program in the previous blog it's time to start writing code! What do you need as a novice programmer If you want to write programs in assembly language you need at least 3 tools: A text editor to write your assembly, An assembler that assembles ("translates")  your assembly language into machine code, A MSX computer (emulator or real) to run your program. You can use 3 separate programs for this and and you probably will when you are more advanced, but to get started there is a perfect all-in-one solution: MSXPen! It's even webbased so you don't have to install anything and you can use it right away on most operating systems. Visit the website https://msxpen.com/  and you'll see something like this: On the left side of the screen are two tabs where you can switch between a text editor to write MSX BASIC code and a text editor for assembly language (Asm) . On the right side is an em
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#1 - Hello world! (part 1 of 2 - basic knowledge)

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So, this is the first real post on MSX machinecode programming. I'm afraid it will be quite long as you do need to have some basic knowledge before you can start programming. You really need to know something about: The parts of a MSX-computer Numbers and the number system The Z80 processor I'll try to keep it as short as possible, but still understandable. At the end of this blog we will have a working program that writes "Hello world!" on the screen.    Oops, sorry, not true. This blog got so long that I've decided to split this up into 2 parts: "basic knowledge" and "programming our 'Hello world!' "   I promise that part 2 will be there very soon! But first a tip! I'm trying to make this blog as good as possible, but there are many other sources where you can find information and I want to encourage you to use them. So find yourself websites, PDF-documents, textfiles, Youtube-video's, books and so on. Get all the information
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